Omg I've wanted to get into this so bad.
I know it would be a great idea for makeup. Food and such I'm not so sure since I only eat fresh fruits, vegetables, and some rice.
I recently opened a newspaper with tons of coupons for hair dye and all kinds of makeup. You could easily use them at RiteAid or WalGreens and pair the manufacturers' coupons with the drug store coupons. They had 40% off coupons for one item from the store.
So basically:
$1.00 off any Cover Girl Mascara
40% off any ONE (1) item.
From $6.00 to ~$2.50, WOW. I could get two! You can never have enough makeup.
I'd love to start a coupon train.